The rollers in a roller bed of a continuous casting machine operate in an adverse environment with high temperature, water, oxide scales and steam, which is generated when the water is used for cooling the hot casting strands, which are shaped, transported and cooled on the roller bed, where every roller is subdivided in several roller segments. This puts very high demands on the sealing arrangements for the bearings in which these roller segments are supported on the shaft common for several or all roller segments. A further complication is the temperature variations to which the rollers are subjected. The volume of air trapped in the gap between a roller segment having a length of about 60 cm and the intermediate sleeve, which is disposed between the shaft and the roller segment, can amount to about half a liter, and the increase in volume this air will experience when heated by the hot casting strands can result in a strong pressure influence on the bearing seals in the absence of devices which could take up such volume increases.
It has been proposed in the past to build bellows-formed compensating devices in or in the vicinity of the bearing housings. Such a solution is presented in SE 526 177 C2. However, at the top rollers of a roller bed, it is quite difficult to use such a solution for space reasons.